Flame arrester and safety relief for vapor lines



y 9. 1933. E. H. JONES 1,907,976

FLAME ARRESTER AND SAFETY RELIEF FOR VAPOR LINES Filed Jan. 9, 1929 1 /0.4 u I l l 0, INVENTOR.

I $3, 15722222" .15. Jones .1 7 I 4 60m: $5.9 9. B1

A TTORNEY,

Patented May 9, 1933 UNITED STATES PATENT OFFICE ELMER H. JONES, OFSOUTH PASADENA, CALIFORNIA, ASSIGNOR TO UNION OIL COM- PANY OFCALIFORNIA, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALI- FORNIAFLAME ARRESTER AND SAFETY BELIEF FOR VAPOR LINES Application filed.January 9, 1929. Serial No. 331,260.

This invention relates to devices to prevent the propagation of flamethrough vapor lines and torelieve excessive pressures therein resultingfor example from explosions, the invention being applicable especiallyto vapor lines connected with storage tanks and other apparatus adaptedto the handling of petroleum and petroleum products.

It has become a common practice to connect petroleum storage tanks withlines by means of which vapors developing in the tanks may be withdrawnfor the two-fold purpose of recovering the valuable contents of thevapors and of eliminating lire hazard by removal of the vapors from thevicinity of the tank. However, one difficulty has been found in the factthat if a fire or an explosion occurs in one tank the flame or thecompression waves may be transmitted to other tanks by way of the vaporlines.

The object of the present invention, therefore, is to provide in thevapor connections leading from various tanks or other apparatus, meansadapted to prevent spread of flame from one tank to another or throughthe main vapor draw-off line.

The invention in its broad aspect resides in a device for use on vaporlines connecting tanks and the like, which device comprises a valveadapted to open readily upon the development of a predetermined pressurefor the relief of such pressure as might develop by explosion inconjunction with an improved device which will cool products ofexplosion or burning gases, and by frictional resistance or the likewill dampen the compression waves, to an extent sufficient to pre ventthe propagation of flame or pressure to other parts of the apparatus.Therefore the relief valve should be placed in advance of theeooling andresistance device, in order that the pressure confined by the latter mayactuate said valve. In a preferred form the pressure relief may besimply a weighted cap or disc normally retained in position by gravity,and the device for preventing propagation of flame and compression\vaves may be a bank of small tubes closely packed in a nipple orsection of pipe forming a part of the draw-off line.

roster comprises a metal shell or section of In the accompanying drawingwherein a preferred embodiment of the invention is shown for purposes ofillustration,

Fig. 1 is a vertical section through the flame arrester and reliefdevice hereof;

Fig. 2 is a plan View indicating how the devices are connected with aplurality of stor age tanks and with a lead-olf'line;

Fig. 3 is a fragmentary cross sectional detail as indicated by line 3-3of Fig. 1; I

Fig. 4 is an enlarged'vertical sectional detail ofthe gravity pressurerelief valve; and

Fig. 5 is a detail of a modified cooling and resisting element.

Fig. 2 discloses a pair of petroleum storage tanks T with which alead-off line L com municates through the medium of connections 10 andthe arresters of the present invention indicated generally at F. Eachartubing 12 which is horizontally disposed when in operation and ispacked with a large number of small tubes 14 (for example, oneeighthinch or one-tenth inch inside diameter) extending longitudinallytherethrough, these tubes preferably being rorced into the nipple insufficient number to fill the same and retain themselves simply byfriction. To each end of the nipple 12 there is threadedly connected afour-way union 15, one of the outlets of each-union being directedupward and terminating in the form of a knife edge 16 upon which thererests a cap or disc 18 adapted to be lifted for relief of pressure uponthe development of any predetermined maximum pressure, for example,one-half pound per square inch, whereby pressure from an explosion willbe promptly released to the atmosphere. The line L will usually be underslight suction of the vapor gathering system. The end outlet of eachunion 15 is conveniently closed with a plug 20 which may be removed forinspection or to clean out the tubes 14, and the under or lower outletof each union 15 receives a connection 22 leading to an L 24 providedwith suitable fittings 25 for mounting the device between theconnections 10.

In this manner an arrester F as just described is positioned betweeneach storage 100 tank T and the draw-ofi' line L, anda relief valve 18is disposed between each storage tank T and the respective tube bank 14.In normal operation the vapors from a tank T are drawn through one ofthe connections 10 into one of the.unions 15, thence through the tubebank 14 contained within the section 12, and thence through the otherunion 15 and connection 10 to the line L where the vapors are removed toany device in which desired disposition is made. Under these conditionsthe vapor flow is light and the small tubes offer no objectionableresistance. However, should an explosion occur in one of the tanks T therespective tube bank 14 will by reason of the very small passages offera material resistance to rapid dissipation of the suddenly increasedpressure so that the confined gas will displace the nearest valve cap 18thereby venting the explosion or burning gases to the atmosphere. Alsothe bank of tubes 14 will act to absorb and conduct away large amountsof heat to be radiated by section 12, thus decreasing the temperature ofhot gases to such extent that the propagation of flame will be preventedand the possibility of extending a flame of explosion to the line L orto other tanks in the system will be eliminated. Inasmuch as one of theflame arresters F is provided for each tank T, each tank is in realityprotected from explosion in the other tank by two of the arresters, andif it were possible for the flame to pass from one tank through therespective arrester into the line L arresters on the other tanks wouldinsure checking of travel of flame to such other tanks. Additionally arelief valve is positioned before and after each bank of tubes so thatthe pressure is relieved whether it comes from one direction or theother. Also this acts as a safety to insure discharge if one of therelief Valves becomes stuck for any reason.

In Fig. 5 there is shown another device capable of providing desirablysmall passages in the cooling and resisting section. Here a cylindricalcartridge 30 having perforated heads 32 is filled with metal balls 34 ofsuitable heating-absorbing capacity and of a size (e. g. one-fourth inchin diameter) to form small passages which together with their tortuoustrend will offer suflicient resistance to rapid travel of gases. Onehead 32 should be removable and may be provided with an eye 35 forengagement by a hook or other tool to pull the cartridge into positionin the shell 12 where it will be held by friction and to withdraw thesame for replacement thereof or for cleaning of the balls.

The specific embodiment herein disclosed is not to be considered as alimitation but merely illustrative of the generic invention, since manymodifications may be made within the scope of the accompanying claims bythose skilled in the art.

I claim:

1. A safety device for vapor lines comprising a housing containing meansproviding a large number of small passages ofl'ering material resistanceto rapid travel of gases, an inlet connection for the housing, an outletconnection for the housing, and a pressure relief value positionedadjacent the inlet to the housing and in line' with the direction offlow of gases as they approach the housing.

2. A safety device for vapor lines comprising a housing containing heatdissipating and flame arresting means providing a large number of smallpassages adapted to ofl'er material resistance to rapid travel of gasestherethrough, a gas inlet connection for the housing, a gas outletconnection for said housing, and a pressure relief valve connected withsaid housing and in line with the direction of flow of gases.

3. A construction according to claim 2 wherein the pressure relief valveis positioned adjacent the housing inlet.

4. A construction according to claim 1 and a secondpressure relief valveconnected with the housing outlet.

5. A safety device for Vapor lines comprising a shell, a large number ofsmall tubes disposed in said shell to provide small passages .forresisting rapid travel of gases therethrough, said shell and tubes beingof heat conducting material for cooling hot gases, an inlet and anoutlet for said shell and a movable pressure relief valve locatedadjacent the inlet to said shell and having its direction of opening inline with the direction of'the path of the gases adjacent the shell.

Signed at Los Angeles, in the county of Los Angeles and State ofCalifornia, this 4th day of January, A. D. 1929.

' ELMER H. JONES.

